| 摘要 |
A channel section (13) is of generally U-shaped cross-section and is made from glass fibre reinforced concrete. The section can be thin and light and easily man-handled. In order to provide the section with sufficient rigidity during the setting of a concrete back fill around the section, a framework of reinforcing bars (17) is provided spaced from the reinforced concrete channel member by tie bars (18) or an integral rib (25). The reinforcing bars and tie bars (17,18) or rib (25) form a rigid composite structure with the fibre reinforced concrete member which keeps the member rigid while the concrete back fill is drying and which forms a reinforcing structure in the concrete after drying. |
